Researchers broke down death, disease, and disability by county using data on the status of population health from surveys dating between 1990-2010.

There were some drastic differences in life expectancy across the nation. Top counties for both sexes included New York City, San Francisco, and Kings, NY. The top 10 bottom counties for both males and females were all in the South.

Institute for Health Metrics and Evaluation/JAMA

"There are places with the best life expectancy in the world in the U.S., and there are places in Mississippi, for example, or West Virginia where life expectancies are in the mid-60s for men and low 70s for women," Dr. Christopher Murray of the University of Washington, one of the head researchers of the study, explained to NBC News. "That's about the same as a number of poor developing countries."

And though the role of social determinants such as income, education, and inequality were not assessed in this report, the researchers did write that it was more than just eating better or exercising more — we need to change the structure of our health education system in the U.S. if we can expect any notable changes.

Here are some of the other major takeaways from the study:

Women in the U.S. are still living longer than men, but men are closing the gap. In 1985, American women were expected to live 7 years longer than men, but now it's down to a difference of 4.6 years.

Bad habits like poor diet and smoking are more dangerous than pollution or risks from radiation.

More Americans are getting the recommended levels of exercise, but obesity continues to rise.

Americans are more disabled now than they were 10 years ago, the researchers found. Though we're living longer, the number of years Americans spend living with a disability has increased.

And here are two graphs that break down life expectancy by county for males and females.